Torque and power. What do they both mean? A lot of people have trouble understanding these terms, but they are really quite straight-forward.
Torque is force x distance. In automotive terms, torque is a measure of the rotational force produced by an engine. The metric unit of measurement is Newton-meters, which is abbreviated Nm. Newtons is the force and meters is the distance. In an internal combustion engine torque is a product of cylinder pressure and crankshaft throw, which is the distance between the crankshaft centerline and the conrod journal centerline. The more downward pressure on the piston (force), and the longer the crankshaft throw (distance), the more torque the engine will make.
Power is torque x engine RPM. Or in other words, power is a product of torque and engine speed. Power is a measure of the effort needed to move a vehicle over a given distance within a given time. The metric unit of measurement is kilowatts, which is abbreviated kW. More power provides faster acceleration and higher speeds. So for example, if you know a drag racing car’s power output, weight and a few other variables, you can predict its quarter mile time with a quite reasonable degree of accuracy.
So, there you have it! Torque and power. Quite different concepts but definitely interrelated.